
\begin{tikzpicture}
	\tkzDefPoints{0/0/O, 2/0/A, 2/3/B, 0/3/C}
	\tkzDrawSegments(O,A  O,B  O,C)
	\tkzMarkAngle[size=0.3](A,O,B)
	\tkzMarkAngle[size=0.53](B,O,C)
	\tkzLabelAngle[pos=0.5](A,O,B){$1$}
	\tkzLabelAngle[pos=0.8](B,O,C){$2$}

	\tkzLabelPoints[left](O)
	\tkzLabelPoints[right](A, B)
	\tkzLabelPoints[left](C)
\end{tikzpicture}

